[gnome-builder] gui: Save state to disk even when there weren't any page's state to save

[Christian Hergert <chergert src gnome org>]

commit da6233b9ecd14dcfaa97f210b6a80e232d74ba51
Author: vanadiae <vanadiae35 gmail com>
Date:   Thu Jul 8 18:02:57 2021 +0200

    gui: Save state to disk even when there weren't any page's state to save
    
    Currently (after session API rework) if a workspace doesn't have any page opened,
    nothing's saved at all in the session.gvariant file. This is because it is only
    done when the asynchronous operations count reaches zero _and_ only from the
    per-page saving async callbacks. So since there isn't any page to save, the
    callback isn't called and the state is never saved to disk, even if it exists as
    as empty GVariant array.
    
    So to fix this, this commit splits the state saving function into a separate one
    that strictly handles only saving to disk, and call that save to disk function
    when there's no pages to save.

 src/libide/gui/ide-session.c | 86 ++++++++++++++++++++++++++------------------
 1 file changed, 51 insertions(+), 35 deletions(-)
---
diff --git a/src/libide/gui/ide-session.c b/src/libide/gui/ide-session.c
index 05e9e8590..f5ee00d0a 100644
--- a/src/libide/gui/ide-session.c
+++ b/src/libide/gui/ide-session.c
@@ -654,6 +654,51 @@ typedef struct {
   IdePage *page;
 } SavePage;
 
+static void
+save_state_to_disk (IdeSession      *self,
+                    IdeTask         *task,
+                    GVariantBuilder *pages_state)
+{
+  g_autoptr(GVariant) state = NULL;
+  g_autoptr(GBytes) bytes = NULL;
+  g_autoptr(GFile) file = NULL;
+  IdeContext *context;
+  GVariantDict final_dict;
+  /* It seems that because g_steal_pointer is an inline function it'll return "task" and set it
+   * to NULL _then_ try to get the cancellable from it when using this getter inline in the
+   * function call below. This looks like a bug from GCC/whatever, as they don't evaluate
+   * expressions in the right order…
+   */
+  GCancellable *cancellable = ide_task_get_cancellable (task);
+
+  IDE_ENTRY;
+
+  g_variant_dict_init (&final_dict, NULL);
+  g_variant_dict_insert (&final_dict, "version", "u", (guint32) 1);
+  g_variant_dict_insert_value (&final_dict, "data", g_variant_builder_end (pages_state));
+
+  state = g_variant_ref_sink (g_variant_dict_end (&final_dict));
+  g_debug ("Saving session state for all pages with %s", g_variant_print (state, TRUE));
+  bytes = g_variant_get_data_as_bytes (state);
+
+  context = ide_object_get_context (IDE_OBJECT (self));
+  file = ide_context_cache_file (context, "session.gvariant", NULL);
+
+  if (ide_task_return_error_if_cancelled (task))
+    IDE_EXIT;
+
+  g_file_replace_contents_bytes_async (file,
+                                       bytes,
+                                       NULL,
+                                       FALSE,
+                                       G_FILE_CREATE_NONE,
+                                       cancellable,
+                                       on_state_saved_to_cache_file_cb,
+                                       g_object_ref (task));
+
+  IDE_EXIT;
+}
+
 static void
 on_session_addin_page_saved_cb (GObject      *object,
                                 GAsyncResult *result,
@@ -710,40 +755,7 @@ on_session_addin_page_saved_cb (GObject      *object,
 
   if (s->active == 0)
     {
-      g_autoptr(GVariant) state = NULL;
-      g_autoptr(GBytes) bytes = NULL;
-      g_autoptr(GFile) file = NULL;
-      IdeContext *context;
-      GVariantDict final_dict;
-      /* It seems that because g_steal_pointer is an inline function it'll return "task" and set it
-       * to NULL _then_ try to get the cancellable from it when using this getter inline in the
-       * function call below. This looks like a bug from GCC/whatever, as they don't evaluate
-       * expressions in the right order…
-       */
-      GCancellable *cancellable = ide_task_get_cancellable (task);
-
-      g_variant_dict_init (&final_dict, NULL);
-      g_variant_dict_insert (&final_dict, "version", "u", (guint32) 1);
-      g_variant_dict_insert_value (&final_dict, "data", g_variant_builder_end (&s->pages_state));
-
-      state = g_variant_ref_sink (g_variant_dict_end (&final_dict));
-      g_debug ("Saving session state for all pages with %s", g_variant_print (state, TRUE));
-      bytes = g_variant_get_data_as_bytes (state);
-
-      context = ide_object_get_context (IDE_OBJECT (self));
-      file = ide_context_cache_file (context, "session.gvariant", NULL);
-
-      if (ide_task_return_error_if_cancelled (task))
-        IDE_EXIT;
-
-      g_file_replace_contents_bytes_async (file,
-                                           bytes,
-                                           NULL,
-                                           FALSE,
-                                           G_FILE_CREATE_NONE,
-                                           cancellable,
-                                           on_state_saved_to_cache_file_cb,
-                                           g_steal_pointer (&task));
+      save_state_to_disk (self, task, &s->pages_state);
     }
 
   IDE_EXIT;
@@ -837,9 +849,13 @@ ide_session_save_async (IdeSession          *self,
 
   g_assert (s != NULL);
 
+  /* Save the empty pages state there too because it wouldn't have
+   * been done in foreach_page_in_grid_save_cb() since there's no
+   * pages to save.
+   */
   if (s->active == 0)
     {
-      ide_task_return_boolean (task, TRUE);
+      save_state_to_disk (self, task, &s->pages_state);
       IDE_EXIT;
     }